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86Sr, δ7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean’ [Geochim. Cosmochim. Acta 73 (2009) 5444–5459]
Available online at www.sciencedirect.com
ScienceDirect Geochimica et Cosmochimica Acta 152 (2015) 52–53 www.elsevier.com/locate/gca
Corrigendum Corrigendum to ‘Isotopic evidence (87Sr/86Sr, d7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean’ [Geochim. Cosmochim. Acta 73 (2009) 5444–5459]
The authors regret: We have been made aware of an error in the calculation of lithium (Li) isotope fractionation factors and temperatures for fluid–sediment and fluid–rock interactions (Table 5 in Scholz et al. (2009)). The corrected values calculated using Eqs. (1)–(4) in Scholz et al. (2009) are listed in Table 1. Some of the corrected temperature estimates are substantially lower than the originally published values and therefore require an alternative interpretation. Pore fluids of all mud volcanoes studied by Scholz et al. (2009) show clear indications for clay dehydration processes at depth, such as negative chlorinity anomalies and inversely correlated oxygen and hydrogen isotopes (Da¨hlmann and de Lange, 2003). Clay dehydration reactions generally take place at temperatures between 60 °C and 150 °C (e.g., Kastner et al., 1991). The corrected temperature estimates for the mud volcanoes Captain Arutyunov, Carlos Ribeiro and Bonjardim fall below the lower temperature limit for clay dehydration. This observation suggests that the deep-sourced pore fluids at these locations are strongly affected by shallow alteration processes involving uptake of isotopically light Li by secondary minerals at low temperature. A more comprehensive discussion of Li isotope fractionation during fluid transport and other factors leading to variability in the Li concentration and isotope composition of mud volcano fluids in the Gulf of Cadiz is given in Scholz et al. (2010). Additional uncertainty in the calculation of temperatures for fluid–sediment and fluid–rock interactions is related to the unknown extent to which the original seawater Li has undergone exchange with ambient sediments and rocks as well as to past variability in the seawater Li concentration and isotope composition (e.g., Misra and Froelich, 2012). The authors would like to apologise for any inconvenience caused. References Da¨hlmann A. and de Lange G.J. (2003) Fluid-sediment interactions at Eastern Mediterranean mud volcanoes: a stable isotope study from ODP Leg 160. Earth Planet. Sci. Lett. 212, 377–391. Kastner M., Elderfield H. and Martin J.B. (1991) Fluids in Convergent Margins: what do we know about their composition, origin, role in diagenesis and importance for oceanic chemical fluxes. Philos. Trans. R. Soc. Lond. A 335, 243–259. Misra S. and Froelich P.N. (2012) Lithium isotope history of Cenozoic seawater: changes in silicate weathering and reverse weathering. Science 335, 818–823. Scholz F., Hensen C., Reitz A., Romer R.L., Liebetrau V., Meixner A., Weise S.M. and Haeckel M. (2009) Isotopic evidence (87Sr/86Sr, d7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean. Geochim. Cosmochim. Acta 73, 5444–5459. Scholz F., Hensen C., De Lange G.J., Haeckel M., Liebetrau V., Meixner A., Reitz A. and Romer R.L. (2010) Lithium isotope geochemistry of marine pore waters – insights from cold seep fluids. Geochim. Cosmochim. Acta 74, 3459–3475.
DOI of original article: 10.1016/j.gca.2009.06.004. http://dx.doi.org/10.1016/j.gca.2015.01.001 0016-7037/Ó 2015 Elsevier Ltd. All rights reserved.
Corrigendum / Geochimica et Cosmochimica Acta 152 (2015) 52–53
53
Table 1 Corrected Li isotope fractionation factors for fluid–sediment and fluid–rock interactions at five mud volcanoes in the Gulf of Cadiz. Sampling location
LiPF (lM)
d7LiPF (&)
fSW
fINT
d7LiINTa (&)
aSP-INTb
T (°C)
Mercator MV CAMV CRMV Bonjardim MV Porto MV
2980 463 120 177 99
+12.3 +16.8 +19.9 +19.6 +12.1
0.01 0.06 0.22 0.15 0.13
0.99 0.94 0.78 0.85 0.87
+12.1 +16.0 +16.8 +17.6 +9.3
0.988 0.984 0.983 0.983 0.991
98 41 30 21 159
a b
Calculated assuming d7LiSW = 31(&). Calculated assuming d7LiSP = 0(&).
Florian Scholz
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Christian Hensen
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Anja Reitz
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Rolf L. Romer
Deutsches GeoForschungsZentrum, GFZ, Potsdam, Germany
Volker Liebetrau
Helmholtz Centre for Environmental Research, UFZ, Halle, Germany
Anette Meixner
Deutsches GeoForschungsZentrum, GFZ, Potsdam, Germany
Stephan M. Weise
Helmholtz Centre for Environmental Research, UFZ, Halle, Germany
Matthias Haeckel
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
ScienceDirect Geochimica et Cosmochimica Acta 152 (2015) 52–53 www.elsevier.com/locate/gca
Corrigendum Corrigendum to ‘Isotopic evidence (87Sr/86Sr, d7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean’ [Geochim. Cosmochim. Acta 73 (2009) 5444–5459]
The authors regret: We have been made aware of an error in the calculation of lithium (Li) isotope fractionation factors and temperatures for fluid–sediment and fluid–rock interactions (Table 5 in Scholz et al. (2009)). The corrected values calculated using Eqs. (1)–(4) in Scholz et al. (2009) are listed in Table 1. Some of the corrected temperature estimates are substantially lower than the originally published values and therefore require an alternative interpretation. Pore fluids of all mud volcanoes studied by Scholz et al. (2009) show clear indications for clay dehydration processes at depth, such as negative chlorinity anomalies and inversely correlated oxygen and hydrogen isotopes (Da¨hlmann and de Lange, 2003). Clay dehydration reactions generally take place at temperatures between 60 °C and 150 °C (e.g., Kastner et al., 1991). The corrected temperature estimates for the mud volcanoes Captain Arutyunov, Carlos Ribeiro and Bonjardim fall below the lower temperature limit for clay dehydration. This observation suggests that the deep-sourced pore fluids at these locations are strongly affected by shallow alteration processes involving uptake of isotopically light Li by secondary minerals at low temperature. A more comprehensive discussion of Li isotope fractionation during fluid transport and other factors leading to variability in the Li concentration and isotope composition of mud volcano fluids in the Gulf of Cadiz is given in Scholz et al. (2010). Additional uncertainty in the calculation of temperatures for fluid–sediment and fluid–rock interactions is related to the unknown extent to which the original seawater Li has undergone exchange with ambient sediments and rocks as well as to past variability in the seawater Li concentration and isotope composition (e.g., Misra and Froelich, 2012). The authors would like to apologise for any inconvenience caused. References Da¨hlmann A. and de Lange G.J. (2003) Fluid-sediment interactions at Eastern Mediterranean mud volcanoes: a stable isotope study from ODP Leg 160. Earth Planet. Sci. Lett. 212, 377–391. Kastner M., Elderfield H. and Martin J.B. (1991) Fluids in Convergent Margins: what do we know about their composition, origin, role in diagenesis and importance for oceanic chemical fluxes. Philos. Trans. R. Soc. Lond. A 335, 243–259. Misra S. and Froelich P.N. (2012) Lithium isotope history of Cenozoic seawater: changes in silicate weathering and reverse weathering. Science 335, 818–823. Scholz F., Hensen C., Reitz A., Romer R.L., Liebetrau V., Meixner A., Weise S.M. and Haeckel M. (2009) Isotopic evidence (87Sr/86Sr, d7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean. Geochim. Cosmochim. Acta 73, 5444–5459. Scholz F., Hensen C., De Lange G.J., Haeckel M., Liebetrau V., Meixner A., Reitz A. and Romer R.L. (2010) Lithium isotope geochemistry of marine pore waters – insights from cold seep fluids. Geochim. Cosmochim. Acta 74, 3459–3475.
DOI of original article: 10.1016/j.gca.2009.06.004. http://dx.doi.org/10.1016/j.gca.2015.01.001 0016-7037/Ó 2015 Elsevier Ltd. All rights reserved.
Corrigendum / Geochimica et Cosmochimica Acta 152 (2015) 52–53
53
Table 1 Corrected Li isotope fractionation factors for fluid–sediment and fluid–rock interactions at five mud volcanoes in the Gulf of Cadiz. Sampling location
LiPF (lM)
d7LiPF (&)
fSW
fINT
d7LiINTa (&)
aSP-INTb
T (°C)
Mercator MV CAMV CRMV Bonjardim MV Porto MV
2980 463 120 177 99
+12.3 +16.8 +19.9 +19.6 +12.1
0.01 0.06 0.22 0.15 0.13
0.99 0.94 0.78 0.85 0.87
+12.1 +16.0 +16.8 +17.6 +9.3
0.988 0.984 0.983 0.983 0.991
98 41 30 21 159
a b
Calculated assuming d7LiSW = 31(&). Calculated assuming d7LiSP = 0(&).
Florian Scholz
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Christian Hensen
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Anja Reitz
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Rolf L. Romer
Deutsches GeoForschungsZentrum, GFZ, Potsdam, Germany
Volker Liebetrau
Helmholtz Centre for Environmental Research, UFZ, Halle, Germany
Anette Meixner
Deutsches GeoForschungsZentrum, GFZ, Potsdam, Germany
Stephan M. Weise
Helmholtz Centre for Environmental Research, UFZ, Halle, Germany
Matthias Haeckel
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany